For Viewers, disable UI Icons that cannot be engaged with

[clayandgen]

For viewers (and other roles without necessary permissions), disable icons that they can't engage with, like:

• Admin Console (hide this for non-admins)
• Edit on Tlm Viewer / Create Screen on Tlm Viewer

Making the UI handle some authz instead of solely relying on API

[jmthomas]

Make the Admin console not throw errors. Disable buttons for non-admin users. We still want to allow viewers to be able to see what plugins are installed and the microservices that are running.

Disable the View button (eyeball) for microservices unless you're admin.